Yeah my inventory items are being stolen too.
First, was a bunch of furniture.
Second, a plant pet a friend had very generously given me from his store as a gift, valued at 500L.
Thirdly, and most recently, 3 clothing items I bought just the other night, and which had disppeared the next day when I signed ...I've NC'd the owner but have yet to hear back from her.
This is seriously annoying, and I have tried numerous suggestions from the forums, on how to get these items back, but nothing seems to work.
Thankfully, when I uninstalled 2.4 and went back to 2.3, that fixed the graphics/rezzing problems I was having. So, at least that issue is no longer a problem.